On the Development of a Bifunctional TGF-β1/PD-L1 Fusion Protein for Targeted Immunomodulation in Autoimmune Diseases

This research accompanies a study abstract that reports the design, expression, and in vitro functional characterization of a novel bifunctional fusion protein composed of transforming growth factor-beta 1 (TGF-β1) and programmed death-ligand 1 (PD-L1). The fusion protein was engineered with domain-specific linkers to preserve dimeric structure and independent receptor-binding activity. Expressed in a mammalian system (HEK293), the construct was validated using SDS-PAGE, immunoprecipitation, western blot, and co-immunoprecipitation assays. Functional activity was assessed through receptor engagement and downstream gene expression profiling in leukemic cell models.Results demonstrated successful binding to TGFβ-R1 and PD-1 receptors, as well as activation of relevant signaling pathways, supporting its immunomodulatory potential. The protein construct is the subject of U.S. Patent No. US11912751B2 and may serve as a molecular template for the development of next-generation immunotherapeutics, particularly in the context of autoimmune disease therapy and checkpoint-targeted biologics. This work may be of interest to researchers in synthetic biology, therapeutic protein engineering, and immune regulation.